Gesneriads: African Violets, Gloxinias, Streptocarpus and Others 9780995435681

Table of contents :
CHAPTER 1 INTRODUCTION
COMMERCIAL SIGNIFICANCE OF GESNERIADS
Uses of Gesneriads
CHAPTER 2 GENERAL CULTURAL REQUIREMENTS
HOW TO GROW GESNERIADS
Saintpaulia
Sinningia
Achimenes
Kohleria
Streptocarpus
Columnea
Propagation of Gesneriads
Kohleria
Saintpaulia
Sinningias
Achimenes
Kohlerias and other rhizomatous gesneriads
Streptocarpus
Columneas
CHAPTER 3 BOTANICAL CHARACTERISTICS
GENERAL BOTANICAL DESCRIPTION
Roots
Fibrous rooted gesneriads
Tuberous gesneriads
Scaly rhizomatous gesneriads
Stems
Leaves
Flowers
Corolla
Stamens
Nectar
PART 2: PLANT DIRECTORY
ACHIMENES
AESCHYNANTHUS (syn. Trichosporum)
ALLOPLECTUS
ASTERANTHA
BELLONIA
BESLERIA
BOEA
BRIGGSIA
CAPANEA
CHIRITA
CHRYSOTHEMIS
COLUMNEA
CYRTANDRA
EPISCIA (syn. Alsobia)
GESNARIA
KOHLERIA
NAUTILOCALYX
NEMATANTHUS
NIPHAEA (syn. Meneghinia)
RHYNCHOGLOSSUM (syn. Klugia)
RAMONDA (sometimes spelled ‘Ramondia’)
Saintpaulia (African Violet)
Classification Systems and Changes to Classifying Saintpaulia
Size Classifications of Saintpaulia Species
A general guide to size categories:
Saintpaulia Species and Their Newer Classifications
More about S. ionantha
SINNINGIA (GLOXINIA)
SMITHIANTHA (Temple Bells)
STEPTOCARPUS (Cape primrose)
Further reading and study

Citation preview

Contents Chapter 1 introduction

5

Commercial significance of Gesneriads

9

Uses of Gesneriads

12

Chapter 2 general cultural requirements

13

How to grow Gesneriads

14

Saintpaulia

14

Sinningia

15

Achimenes

16

Kohleria

16

Streptocarpus

16

Columnea

17

Propagation of Gesneriads

18

Kohleria

18

Saintpaulia

18

Sinningias

20

Achimenes

21

Kohlerias and other Rhizomatous Gesneriads

21

Streptocarpus

21

Columneas

23

Chapter 3 botanical characteristics

24

General botanical description

24

Roots

24

Fibrous rooted Gesneriads

24

Tuberous Gesneriads

25

Scaly Rhizomatous Gesneriads

25

Stems

25

Leaves

26

Flowers

28

Corolla

29

Stamens

29

Nectar

29

Chapter 4 plant directory

30

Achimenes

30

Aeschynanthus (syn. Trichosporum)

30

Alloplectus

33

Asterantha

33

Bellonia

33

Besleria

33

Boea

33

Briggsia

33

Capanea

33

Chirita

33

Chrysothemis

35

Columnea

36

Cyrtandra

37

Episcia (syn. Alsobia)

37

Gesnaria

38

Kohleria

39

Nautilocalyx

39

Nematanthus

39

Niphaea (syn. Meneghinia)

40

Rhynchoglossum (syn. Klugia)

41

Ramonda (sometimes spelled ‘Ramondia’)

41

Saintpaulia (African Violet)

42

Classification systems and changes to classifying Saintpaulia

43

Size classifications of Saintpaulia species

44

A general guide to size categories

45

Saintpaulia species and their newer classifications

45

More about S. Ionantha

47

Sinningia (Gloxinia)

50

Smithiantha (Temple Bells)

53

Streptocarpus (Cape Primrose)

53

Further reading and study

62

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Credits © Copyright 2017 John Mason Written By: Staff of ACS Distance Education Photos: John Mason and Stephen Mason Layout & Illustration: Stephen Mason Editorial Assistants/Contributors: John Mason Dip.Hort.Sc., FCIH, FAIH, FPLA Gavin Cole B.Sc. Marie Beermann B.Sc. Hort., M.Sc. Hort., PDC Adriana Fraser Cert.Hort., Adv.Dip.Hort. Published by: ACS Distance Education P.O. Box 2092, Nerang MDC, Queensland, Australia, 4211 [email protected] www.acsbookshop.com P O Box 4171, Stourbridge, DY8 2WZ, United Kingdom [email protected] www.acsebooks.com

ISBN: 978-0-9954356-8-1

page 4

The information in this book is derived from a broad cross-section of resources (research, reference materials and personal experience) from the authors and editorial assistants in the academic department of ACS Distance Education. It is, to the best of our knowledge, composed as an accurate representation of what is accepted and appropriate information about the subject, at the time of publication. The authors fully recognise that knowledge is continually changing, and awareness in all areas of study is constantly evolving. As such, we encourage the reader to recognise that nothing they read should ever be considered to be set in stone. They should always strive to broaden their perspective and deepen their understanding of a subject, and before acting upon any information or advice, should always seek to confirm the currency of that information, and the appropriateness to the situation in which they find themselves. As such, the publisher and author do not accept any liability for actions taken by the reader based upon their reading of this book.

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CHAPTER 1 INTRODUCTION Gesneriaceae is a diverse family of plants that includes over 2,000 different species, spread across more than 120 genera. Around 300 or more of the species are in cultivation.

Gloxinia species Genera in this family include: Acanthonema, Achimenes, Aeschynanthus, Agalmyla, Allocheilos, Alloplectus, Allostigma, Alsobia, Amalophyllon,, Ancylostemon, Anetanthus, Anna, Asteranthera, Beccarinda, Bellonia, Besleria, Boea, Boeica, Bournea, Briggsia, Briggsiopsis, Brookea, Bucinellina, Calcareoboea, Cathayanthe, Championia, Charadrophila, Chautemsia, Chirita, Chiritopsis, Chrysothemis, Cobananthus, Codonanthe, Codonanthopsis, Colpogyne, Columnea, Conandron, Corallodiscus, Coronanthera, Corytoplectus, Crantzia, Cremersia, Cremosperma, page 5

Cremospermopsis, Cubitanthus, Cyrtandra, Cyrtandromoea, Dalbergaria, Dayaoshania, Deinocheilos, Deinostigma, Depanthus, Diastema, Didissandra, Didymocarpus, Didymostigma, Dolicholoma, Drymonia, Emarhendia, Episcia, Epithema, Eucodonia, Fieldia, Gasteranthus, Gesneria, Glossoloma, Gloxinella, Gloxinia, Gloxiniopsis, Goyazia, Gyrocheilos, Gyrogyne, Haberlea, Hemiboea, Hemiboeopsis, Henckelia, Heppiella, Hexatheca, Hovanella, Isometrum, Jancaea, Jerdonia, Kaisupeea, Kohleria, Lagarosolen, Lampadaria, Lembocarpus, Lenbrassia, Leptoboea, Linnaeopsis,

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Litostigma, Loxonia, Loxostigma, Lysionotus, Mandirola, Metabriggsia, Metapetrocosmea, Micraeschynanthus, Mitraria, Monophyllaea, Monopyle, Moussonia, Napeanthus, Nautilocalyx, Negria, Nematanthus, Neomortonia, Niphaea, Nodonema, Nomopyle, Oerstedina, Opithandra, Orchadocarpa, Oreocharis, Ornithoboea, Paliavana, Paraboea, Paradrymonia, Paraisometrum, Paralagarosolen, Pearcea, Pentadenia, Petrocodon, Petrocosmea, Pheidonocarpa, Phinaea, Phylloboea, Platystemma, Primulina, Pseudochirita, Ramonda, Raphiocarpus, Rehmannia, Reldia, Resia, Rhabdothamnopsis, Rhabdothamnus, Rhoogeton, Rhynchoglossum, Rhynchotechum, Rhytidophyllum, Ridleyandra, Rufodorsia, Saintpaulia, Sanango, Sarmienta, Schizoboea, Seemannia, Senyumia, Sepikea, Shuaria, Sinningia, Smithiantha, Solenophora, Sphaerorrhiza, Spelaeanthus, Stauranthera, Streptocarpus, Tengia, Tetraphyllum, Thamnocharis, Titanotrichum, Trachystigma, Tremacron, Trichantha, Trisepalum, Tydaea, Tylopsacas, Vanhouttea, Wentsaiboea, Whytockia

Chirita tamiana

Episcia sp.

Note: some of these may be redundant (old) names.

Aeschynanthus ‘Big Apple’

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Haberlea rhodopensis

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Streptocarpus ‘Harlequin Purple’

Rhytidophyllum exsertum Petrocosmea minor

Petrocosmea iodioides

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Seemannia sylvatica

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Streptocarpus ‘Bethan’

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COMMERCIAL SIGNIFICANCE OF GESNERIADS Members of the Gesneriaceae family, or gesneriads as they are commonly known, have the greatest commercial value as ornamental plants. In particular, given they originate from tropical and subtropical places they are grown as houseplants in temperate parts of the world. Amongst the most popular species are those known as African Violets, which are species and hybrids of Streptocarpus, section Saintpaulia. These were first discovered in the late 1800s. In 1892, a German officer based in East Africa sent samples to his father in Germany, Baron Ulrich von Saint PaulIllaire. He shared these specimens with the Royal Botanic Gardens in Hanover. Hermann Wendland gave the species Saintpaulia ionantha its name because ‘ionantha’ means “having violet-like flowers” in Greek. Streptocarpus kirkii

Tydaea hybrida nana

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Saintpaulia ‘Bonnie Ross’

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Hybrid seeds became available in Germany in the 1920s, but the name ‘African Violet’ was preferred over their botanical name. By the 1930s seed

houses in America were selling hybrid seeds and their popularity increased rapidly thereafter.

Sinningia bullata Another of the most commercially viable gesneriads are the “Florist’s Gloxinias” which are hybrids of Sinningia speciosa. These are named after the German botanist, Wilhelm Sinning, who worked at the Botanic Gardens of the University of Bonn in Germany in the early 19th century. Today, the many hybrids are usually simply called Gloxinias. They have velvety leaves and mainly have large, symmetrical, trumpet-shaped flowers with either wavy or straight edges. Flowers are available in a wide range of colours, and some may be speckled whilst others are bicoloured. Some have single flowers, and others are doubles. Whilst the name ‘Florist’s Gloxinia’ page 10

may conjure images of cut flowers and floral bouquets, these are really rather delicate plants. The reason they are associated with florists is more likely to be because florists began selling them as decorative potted houseplants. In terms of medicinal value, the gesneriads as a whole are not highly regarded at this time. As with many other types of plant, some have been used by indigenous peoples for assisting with a variety ailments, chiefly in parts of Asia and South America. For example, in South America Drymonia serrulata has been used as a topical treatment of skin eczema in Ecuador, Sinniniga tubiflora has been adopted as a purgative in Argentina, and Besleria

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calantha has reportedly been used to treat snakebite in Ecuador. In Asia, Didymocarpus aromaticus is prepared as an aromatic tea in northern parts of India, Aeschynanthus parviflorus is

said to promote fertility in Nepal, and Loxostigma griffithii has been used to treat sexually transmitted diseases in China.

Streptocarpus ‘Carys’ Today, gesneriads remain popular as indoor plants due to their vibrant floral displays. There are a great many appreciation societies around the world, some specialising in particular plant genera like African Violets and others which are dedicated to the family more generally. Wherever you live, there is probably a society somewhere not too far away which you could join to gain further insights. Societies are often a good source of seeds and plant material, as well as information and growing tips. page 11

Although the popularity of gesneriads has fluctuated over the years, as with many other types of flowers, there are a great many commercial growers and enthusiastic hobbyists who are continuously creating new hybrids. Consequently, there are always some intriguing new flowers being produced which helps to keep these plants to the fore of hybrid grower’s minds.

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Uses of Gesneriads It is perhaps the showy flowers of the commonly cultivated species which growers are most attracted to, although many also have noteworthy leaves.

Gesneriads are perhaps the most significant group of plants for indoor and greenhouse use. Many are relatively small making them suitable where space is at a premium, and all are outstanding in flower.

African violets African Violets have the added benefit of being able to flower throughout the year, which makes them ideal for floral displays such as table decorations and on window ledges. Potted Saintpaulias are used at weddings, funerals, luncheons, ceremonies, and all sorts of other events. Those gesneriads in the Aescynanthus and Episcia genera are trailing types which are suited to growing in hanging baskets and suspended pots. They can also be used in window boxes during summer in milder regions where they will afford a temporary splash of colour. Often they are used in this way with a view to removing them once spent and replacing with other seasonal flowers since none will tolerate colder temperatures. It should be noted that whilst many of the newer hybrids are a little hardier than their parent species, page 12

they still require suitable care and appropriate conditions and will not survive outdoors in temperate climates beyond the warmest summer days.

Saintpaulia ‘Monet’

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CHAPTER 2 GENERAL CULTURAL REQUIREMENTS Gesneriads occur mostly in tropical and subtropical regions, though there are some exceptions. The family has representative genera from most parts of the world, including Europe, Africa, Asia, America, Australasia and Polynesia. Some of the genera (including Saintpaulia, Streptocarpus and Sinningia) have been widely bred to produce thousands of different named cultivars, some of which have become commercially important plants. The first gesneriad identified was Ramonda myconi, from northern Spain

Streptocarpus ‘Harlequin Lace’

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and the Pyrenees. It occurs naturally on rocky cliffs. Its classification was confused when it was first discovered. It was thought to be an Auricula to begin with but then Linnaeus in 1753 classified it as a Verbascum. Eventually it was recognised as belonging to a different family to those plants.

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HOW TO GROW GESNERIADS All gesneriads require warm conditions, some shade, and moist soils. They will not thrive in heavy shade, so if used as indoor plants, don’t attempt to grow them in poorly lit rooms. Instead it is best to grow them where they will get at least some light from windows but are not in direct sunlight. Nevertheless, there are some gesneriads, such as African Violets, which will grow well in relatively sunny conditions providing they are kept well-watered. However, you should avoid getting water on the flowers and foliage in these situations since they are likely to become sun scorched. Cultivation practices for some of the more common species follow.

Shorter plants like Saintpaulia form basal rosettes in a tight swirl

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Saintpaulia Saintpaulias are usually grown as indoor or houseplants in temperate climates. They are best grown in a peaty loam. If you make your own mix, equal parts by volume of loam, peat, leaf mould and sand is ideal. ●● Soil should be kept moist but not wet. ●● They can be grown in 12 to 15cm

pots with the pots placed inside trays of gravel and water.

●● Feed with liquid fertiliser every

couple of weeks from late spring to early autumn.

Another option is to grow them inside a terrarium indoors. This way, you can maintain humidity and warmth and grow them along with other tropical plants. In this kind of setup, it is important to only use plants which thrive in warm, moist conditions. Saintpaulias should be repotted every couple of years in spring.

Saintpaulia ‘Flower Drum’

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Sinningia Sinningias are best grown as greenhouse plants in all but subtropical and tropical climates. They can be grown in the greenhouse from tubers planted in late winter.

maintain the temperature at 21°C. ●● When the young plants reach 5 to

6cm tall put them into separate pots.

●● You should position the top of the

tubers level with the surface of the potting mix.

●● Continue to grow the tubers in the

greenhouse, feeding with liquid fertiliser every ten days or so once the first flower buds emerge.

●● Keep the temperature between 18

and 21°C, and keep the soil moist but not wet.

●● After flowering, remove the dead

Sinningia concinna Plant the tubers in trays of peaty loam or good quality seed-raising mix and

Sinningia leucotricha

page 15

foliage and flowers and store the tubers dry between 12 and 16°C.

Replace the old tubers with new ones every few years. Smithiantha or Temple Bells are treated similarly to Sinningias.

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Achimenes Achimenes are typically grown as indoor pot plants and are relatively easy to care for. They can be grown from rhizomes in early spring. Like Saintpaulias and Sinningias, they prefer a peaty soil. ●● Plant half a dozen rhizomes 2 to

3cm deep in a 12cm pot. Achimenes are also known as ‘hot water plants’ since if you soak the rhizomes in hot water before planting they will reach maturity more quickly.

●● Once planted, don’t over-water but

water lightly until they begin to grow. Then keep moist and feed with liquid fertiliser every couple of weeks once flower buds emerge.

●● Grow them in 15 to 20cm pots in a

peaty loam.

●● Maintain temperatures of 10°C from

late autumn through to early spring, and then 13°C from mid spring to mid-autumn.

●● Keep the plants moist during the

growing season and only just moist over winter.

●● Feed every couple of weeks with

liquid fertiliser during growth.

●● Stake the flower stems for support.

Deadhead after flowering.

●● Due to the weight of flowers, the

stems usually need supporting by tying to flower sticks or canes.

●● After they have flowered allow the

plants to dry during autumn.

Kohleria Kohlerias, being rhizomatous, are grown in the same way except without hot water treatment. Plant about 3 rhizomes in a 12cm pot or about 5 to 6 rhizomes in an 18-20cm pot.

Streptocarpus Streptocarpus species are a little different to the other gesneriads mentioned in that they are best grown in cool greenhouse conditions.

page 16

Streptocarpus ‘Adele’

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Streptocarpus ‘Caitlin’ The single-leaved species are usually replaced each year since they only flower once. Tufted species should be re-potted every spring.

Columnea Columnea species are suited to growing in hanging baskets to show off their hooded flowers which emerge from the leaf axils. ●● Baskets should be 25 to 30cm and

contain a peaty loam.

●● Those species that are summer-

flowering need to be kept at temperatures of 10 to 13°C over the winter.

●● Those which flower in winter should

be kept at 13 to 16°C over the winter.

●● Water the plants during the growing

season and avoid temperatures of 18° or over.

Streptocarpus ‘Harlequin Blue’

page 17

●● Feed with liquid fertiliser every ten

days during growth.

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●● Mist plants to provide humidity. ●● Deadhead spent flowers and cut

back dead stems.

You can re-pot every couple of years. Do this in summer for winter flowering species and spring or autumn for summer flowering types.

Propagation of Gesneriads Most gesneriads can be grown from seeds, tubers/rhizomes, or leaf cuttings. Your choice may depend upon what plant material you have available. Although the following refer to generally accepted procedures you can try taking cuttings or dividing rhizomes and tubers outside of these timelines to get plants which flower at different times.

Kohleria With Kohleria it is quite possible to have plants flowering throughout the year if you take cuttings every month or so.

Saintpaulia Saintpaulias can be grown from leaf cuttings simply by retaining about 5cm or so of stem on each one. Leaf cuttings can be taken during summer through to early autumn. ●● Insert them into 6 to 10cm pots

containing a suitable propagating mix such as equal parts by volume of sand or vermiculite/perlite and peat, or sand and coir (for a more environmentally friendly choice).

●● Use flower sticks or wooden

skewers to support them.

●● Alternatively, leaf cuttings will also

strike if placed in a jar of water.

●● Support them by securing a piece of

Columnea sp.

page 18

brown paper or hessian to the neck of the jar using an elastic band or twine, and make holes to insert the stems through.

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●● Place the cuttings in a greenhouse

or propagating frame and maintain the temperature at about 18 to 21°C.

The young plants should be potted on when they become too large for the original pots.

African Violet Cutting Saintpaulias can also be grown from seeds. ●● Sow the seeds in spring in trays or

pots of equal parts by volume of peat (or coir), loam and sand. Once again, maintain temperatures at 18 to 21°C.

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●● Seedlings can be pricked out when

large enough to handle without damaging them.

●● Place them in 6 to 10cm pots, and

then once again pot them on when they outgrow their pots.

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Sinningias Sinningias are usually propagated from seeds. Do this in late winter to early spring. ●● Seeds can be sown in a regular

seed propagating mix in trays.

●● Maintain temperature at 21°C. ●● After the second set of true leaves

have emerged, prick out the seedlings and put them into 5 to 6cm pots.

●● Once the seedlings are established

you can lower the temperature to about 18°C.

●● When mature enough pot them on

into larger pots.

Sinningias may also be propagated from leaf cuttings. These should be taken during summer. ●● Using a sharp knife cut the leaves

from the stem.

●● Then slice through the veins on the

underside of the leaves close to the main vein.

●● Place the leaf halves onto the

propagating medium with the cut side facing downwards into the mix.

●● Once again maintain the

temperature at 21°C and new plants will grow along the leaf edge, each with its own root system.

●● These can then be divided off.

Plants can also be propagated by dividing the tubers in early spring so that you have a number of smaller pieces each with one or two growing tips. ●● Plant each of these into

separate pots.

●● Another method is taking 5 to 7cm

long basal shoots each with a slice of tuber attached. Place these in equal parts peat or coir and sand or perlite.

●● Keep in the greenhouse or

propagating frame at 21°C.

Sinningia leucotricha

page 20

●● When they have rooted, pot them on

into individual pots.

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Achimenes Achimenes can be propagated from rhizomes. Each rhizome will provide another four or more during the growing season. Leave the rhizomes in the pots after drying and cut off the young rhizomes the following spring divide for growing new plants.

Kohlerias and other rhizomatous gesneriads For Kohlerias and other rhizomatous gesneriads you can use the same approach as for Achimenes. Just ensure each new segment of rhizome has an eye or growing tip. Kohlerias can also be grown from stem cuttings taken in summer. ●● These should be placed into pots of

equal parts sand or perlite and peat or coir and kept at 16 to 18°C.

●● Once they are rooted, transfer

●● Once seedlings can be handled

without damaging them, prick them out into 10cm pots.

●● Re-pot as needed. ●● Tufted types can be divided during

re-potting in the spring.

You can also easily grow Streptocarpus from leaf cuttings. You can either cut along the veins close to where they meet the main vein on the undersides of the leaves and plant the two halves cut side down, or you can cut three to four sections of leaf retaining a piece of main vein in each. ●● Insert leaf sections in equal parts by

volume of sand or perlite and peat or coir.

●● Maintain the temperature at 18°C. ●● The small plants which develop can

be separated and potted on once they have developed a sufficient root system.

groups of plants into larger pots as described above.

Streptocarpus Streptocarpus can be successfully grown from seed but the time of year you sow them will influence when they flower. If you plant seed in mid-winter you’ll produce plants which flower the following autumn. If you plant seeds in spring they won’t flower until the summer of the year after. Streptocarpus ‘Albatross’

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Streptocarpus ‘Harlequin Delft’

Streptocarpus Leaf Cuttings You can either cut a leaf in two discarding the main central vein or make several cuts to include the central vein, ensuring there are 4 or more sections of leaf. Young plants emerge from veins.

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Columneas Columneas can be propagated from non-flowering stem cuttings taken in spring using the same propagating mix already described. ●● Insert cuttings into trays and

maintain temperatures at 18 to 21°C.

●● Once rooted transfer the plants to

individual 10cm pots.

●● To encourage bushy growth, pinch

out some of the growing stem tips.

●● When sufficiently grown, put three to

four plants in each basket.

Columnea flower

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Columnea sp.

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CHAPTER 3 BOTANICAL CHARACTERISTICS Given the great diversity of genera included in the Gesnericaeae family, it is not really possible to generalise about their botanical characteristics but there are some recurring themes. For example: most gesneriads are not woody; they are generally herbaceous or only slightly woody. Occasionally they may be tuberous; commonly they can be epiphytes, and on rare occasions they may be a shrub or climber. Some have a caudex (a swollen ball-like section of stem at ground level) which stores moisture and from which foliage arises. Others may produce rhizomes or other specialised parts.

GENERAL BOTANICAL DESCRIPTION Roots

also have fibrous roots. Those that are typically fibrous-rooted alone lack the storage tubers or rhizomes. Other than epiphytic gesneriads which can withstand short dry spells, fibrousrooted gesneriads do not tolerate dry conditions for as long as those with storage organs; the soil that they are growing in should never be allowed to completely dry out. Fibrous-rooted species also include some epiphytic species e.g. Aeschynanthus, Codonanthe, Columnea, Nematanthus and also some species of Sinningia. Epiphytes are those plants that grow on other plants for support – they are not parasitic in that they do not rob the plant they are growing on of nutrients, but use nutrients that are available from plant debris found within the supporting plants’ crevices etc.

All gesneriads have fibrous roots, but one way of dividing them into cultural groups is on the basis of whether they have underground storage organs. This means grouping them as tuberous, scaly rhizomatous, or fibrous-rooted (for those that lack rhizomes or tubers). The root system consists of a primary root and lateral roots which spread from the basal part of the stem, which is usually underground.

Fibrous-rooted gesneriads Most gesneriads are fibrous rooted those that are tuberous and rhizomatous page 24

Columneas are an example of fibrous-rooted gesneriads.

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Tuberous gesneriads Sinningia are tuberous gesneriads, forming storage organs likened to potato tubers but more often pearshaped or flattish. These tubers help them to withstand drought conditions. The tuber may be below ground but is often exposed above ground i.e. be ‘caudiciform’. An example is Sinningia, where only the bases of the roots are below the ground and the tubers sits on top of the ground. This above ground part is referred to as a ‘caudex’. The size of the tuber differs with the species and also the age of the plant some are known to grow to 1 metre in diameter e.g. those of Sinningia macrostachya. Tuberous gesneriads usually have a dormant period where the plants vegetative and flowering parts die down after flowering and re-sprout the following season.

Gloxinia species, an example of a tuberous rooted gesneriad

page 25

Scaly rhizomatous gesneriads Examples of rhizomatous gesneriads are found in Achimenes, Gloxinia, Kohleria and Smithiana etc., the rhizomes form when the plants become dormant. The scaly rhizomes are underground stems with a similarity to long narrow pine cones or segmented grubs – these underground structures are made up of leaves that are modified into closely packed scales. Unlike most other rhizomes, scaly rhizomes of gesneriads are small and have very little ability to store food. The rhizomes should be potted up once they show signs of breaking dormancy.

Stems The stems can be short or long, and may be hairy or not. While most of what we commonly cultivate are low herbaceous plants or creepers, some are more woody and shrub-like. Those species with short stems have shorter internodes so that the leaves emerging from the stem are more crowded, and in some the stem is barely visible. Some of these shorter stemmed plants have leaves forming in a basal rosette e.g. Saintpaulia, whereas others are said to be ‘rosulate’ since the leaves form a loose tuft rather than a tight swirl. Those with longer stems tend to have the leaves situated at regular intervals along the stem.

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Gesneria species are mostly woody shrubs or sub shrubs. With around 50 species, almost all come from the Caribbean.

Leaves Leaves are usually opposite (decussate) and simple. Less commonly, leaves are formed in a spiral arrangement, and this is usually so for those with leaf rosettes.

Shorter plants like Saintpaulia form basal rosettes in a tight swirl

page 26

Rosulate leaf arrangements are loose tufts of leaves, such as Streptocarpus rexii and S. candidus

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The leaf margin is most often entire or toothed. Common leaf shapes include linear, lanceolate, elliptic, ovate and cordate. Some rare gesneriads are pinnately lobed for example Ridleyandra morganii.

Leaf shapes: ●● Cordate: heart shaped. ●● Elliptic/elliptical: oval shape (about

the same slight tapering at base and apex).

●● Lanceolate: tapering from a rounded

base to a pointed apex.

●● Linear: long and narrow with a

central rib.

African Violet Leaf Types

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●● Ovate: rounded at the bottom and

tapering at the apex.

The leaf surface is commonly hairy, but not always, and is often described as velvety. In some species one of a pair of opposite leaves is smaller than the other. In these anisophyllous plants (i.e. having leaves of different shapes or sizes) sometimes the smaller of the two leaves is more like a stipule, and in some species they fall off the stem to give the appearance of an alternate leaf arrangement. Definition of stipule: a small leaflike appendage to a leaf; it is typically produced in pairs at the base of the leaf stalk.

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Flowers Flowers are cymose i.e. they are borne in flattened or domed clusters containing several branches which arch outwards, with those flowers at the end tips opening before those below. Each cyme emerges from the axils of leaves or bracts. These particular cymes are known as paired-flowered because the terminal flower of each cyme unit is paired with another frontal flower. The number of flower pairs on each flower head varies with the species. Where only one flower occurs in the leaf axils, as in many tropical species, this is due to reduction of one of the flower pair. The flowers are usually irregular, bisexual (female and male parts in the same flower), with five fused petals forming the corolla, five sepals forming the calyx, two carpels fused to form a syncarpus pistil, and most commonly two or four fertile stamens (although there are in fact five stamens in total with the infertile ones reduced to a small size).

Streptocarpus flower

page 28

African Violet – Different Flower Types

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Corolla

Nectar

The corolla feeds into the corolla tube. This tube can be straight, curved, narrow, or flared. Some have a spur to the base for added support.

The nectar is typically found between the stamens and ovary. It is again variable but usually complete and ringshaped, cup-shaped or cylindrical.

Note: the corolla typically forms a whorl within the sepals (the green parts at the base of the flower that protect the bud, collectively known as the calyx) enclosing the reproductive organs of the flower.

●● The ovary has two fused carpels

The lobes of the corolla are usually rounded but sometimes pointed.

●● The ovary itself may be cylindrical,

with a straight or curved style and stigma at the top.

●● The stigma can be insignificant or a

variety of shapes.

globose, ovoid or elongated.

Colours are many and varied and other markings serve to direct insects and birds to nectar within.

The position of the ovary may be superior, semi-inferior or inferior where it is sunk inside the receptacle.

Surrounding the corolla, the sepals of the calyx may be fused or separate. Sometimes there are three longer sepals and two shorter ones but usually the sepals are more or less the same size. They are generally simple shapes such as linear or ovate and typically green, but may be brightly coloured.

Definitions:

Stamens The stamens (the male part of the flower) are divided into a filament and anther which has four pollen chambers. Filament length varies according to the corolla length and shape and they usually arise from the base of the tube. The anthers are often positioned side by side, and they vary in size and shape from species to species.

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●● Superior ovary: a superior ovary is

attached to the receptacle above the attachment of other floral parts. Superior ovaries are known as hypogynous.

●● Semi-inferior ovary: all the floral

parts surround the ovary. Semiinferior ovaries are known as perigynous.

●● Inferior ovary: the ovary is

placed below the rest of the floral segments. Inferior ovaries are known as epigynous.

●● Carpel: carpels are the female

reproductive part of a flower made up of the stigma, style and ovary.

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Chapter 4 PLANT DIRECTORY ACHIMENES Achimenes are perennials with rhizomes mostly from sub-tropical rainforests in Central America. Around 25 species: mostly flowering in summer and autumn. Flowers have a long narrow tube that flares to be much wider at the end; great variation in flower colours. They are often deciduous dying down in cooler weather and regrowing in warmer conditions. ●● Water Achimenes moderately early

in the season; increase watering as the growth rate increases. They require moist, well-drained soil and full sun.

●● They are frost-tender, tolerating to

around 10°C only. Grown as indoor plants or outside in temperate climates over the warmer months.

●● They are susceptible to aphids,

thrips and red spider mites.

●● Propagate by dividing rhizomes; or

stem cuttings. They are grown as hanging basket or greenhouse plant in cool regions outside, but often in shade in hotter climates.

Commonly grown species include: ●● Achimenes antirrhina: to 30cm tall

and 15cm wide, with yellow to cream flowers with purple and red inside the throat.

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●● A. erecta (syn. A. coccinea or A.

pulchella): to 45cm tall and 30cm wide, flowers bright red or pinkish, dark green leaves often reddish underneath.

●● A. grandiflora: to 60 cm tall and

60cm diameter; hairy leaves with reddish under surface, reddish purple flowers with white eye and purple spotted throat. Several cultivars are grown.

●● A. longiflora: stems grow to 30cm

arising from round to pear shaped rhizomes; leaves to 9cm long with a paler to reddish underside. Flowers usually purple or lilac, but occasionally red or white. A range of different named cultivars are grown.

●● Many named cultivars also exist.

AESCHYNANTHUS (syn. Trichosporum) Around 100 species occur across parts of Asia; from subtropical forests in the Himalayas through to parts of New Guinea. Thick lance-shaped leaves are the norm. Commonly they have a trailing growth habit. Normally grown in baskets or as an indoor pot plant in temperate climates and outside in tropical areas. ●● Grow in a well-drained but moist

organic soil, either indoors or outdoors in a frost-free situation.

●● They tolerate more sunlight when

humidity is higher.

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●● Keep well-watered when growing. ●● Avoid temperatures under about

15°C.

●● Propagate from cuttings in spring

or summer. Young growth is susceptible to aphids.

Commonly grown species include: ●● Aeschynanthus bracteatus: to 15cm

tall and 60cm wide; long bright red flowers have darker calyces.

●● A. hildebrandii: to 20cm tall and

30cm wide; bright orange-red flowers with calyx not fused.

●● A. lobbianus: a prostrate plant or

semi-climber 45 to 60 cm tall and wide with glossy green leaves and bright red hooded flowers with a purplish brown calyx.

●● A. longicaulis: to 60cm tall and

90cm wide; with trailing stems and dark orange flowers.

Aeschynanthus ‘Black Pagoda’

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●● A. marmoratus (syn. A. zebrinus): to

60cm tall and 90cm wide with long leaves have a purplish underside and yellow veins on the upper surface; green tubular flowers with purplish blotches.

●● A. pulcher (common name is

Lipstick Plant): to 60cm tall and 30cm wide, this climbing or trailing plant has 3.5cm long bright red tubular flowers with a yellow throat.

●● A. radicans var. lobbianus (syn.

A. lobbianus): common name is Lipstick Vine). This trailing plant is up to 20cm tall and 90cm wide; long, dark green leaves with purplish margins, red flowers with purple calyces.

●● A. speciosus: trailing plant to 15

to 60cm tall and 30 to 45cm wide. It bears clusters of bright orange 5 to 7cm long tubular flowers with dark lips.

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Aeschynanthus lobbianus

Aeschynanthus longicaulis

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ALLOPLECTUS

BESLERIA

Around 65 species: a diverse group of shrubs and vines from South and Central America and the Caribbean.

Approximately 17 species of fibrousrooted from central and south America and the West Indies. Flowers vary in colour: white, yellow orange or red.

●● A. ambiguus: vine with small leaves,

yellow flowers.

●● A. calochlamys: shrub with narrow

BOEA

●● A. capitatus: large bright green

Around 20 species from Burma to Australia: blue white or pink flowers and frequently woolly leaves arising from a basal rosette.

●● A. cristatus: vine with small leaves,

BRIGGSIA

white hairy leaves, yellow and pink flowers. leaves; small yellow and red flowers. yellow flowers.

●● A. nummularia (syn. Hypocyrta):

trailing plant that sometimes produces tuber-like nodules on the stems; red pouch shaped flowers with black and yellow around a narrow throat.

●● A. vittatus: large bright green leaves;

small yellow and red flowers.

ASTERANTHA A creeping shrub with red flowers from Chile; only one species: A. ovata

BELLONIA Limited to Cuba and Hispaniola: small shrubs with white flowers – there are two species: B. spinosa is the only gesneriad with thorns.

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Around 20 species rhizomes from the Himalayas and China: stemless, alpine herbs growing on slender: commonly producing two lipped yellow flowers occasionally with red spots on a lower lip.

CAPANEA Often incorrectly spelled ‘Campanea’ this genus is widely spread across the Americas: around ten species of large shrubs and vines, arising from scaly rhizomes.

CHIRITA Around 100 species: indigenous to wet, semi-shaded sites in tropical Asia. Both low-growing and upright plants exist. Chirita have been moved to other genera, including Primulina and Microchirita, but you will still encounter references to Chirita, especially in older literature.

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●● They need artificial heating over

winter in any frost prone climates. Keep at 13 to 18° over winter and ideally 24° to 30°C in summer.

●● Grow in a freely drained organic

media (e.g. 50% compost and 50% sand and charcoal.

●● Water these plants sparingly in

winter but water freely when growing strongly; susceptible to fungal diseases when not growing.

Common species include: ●● Chirita asperifolia (syn. Liebigia

speciosa): shrubby habit, producing waxy purple and white flowers.

●● C. lavandulaceae (syn. Microchirita

lavandulaceae): large hairy soft green leaves similar to Gloxinia, to

Chirita tamiana

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20cm long. Tubular lavender blue flowers in summer and autumn. ●● C. micromusa (syn. Microchirita

micromusa): to 30cm tall, succulent growth, yellow flowers with an orange throat.

●● C. elphinstonia (syn. Microchirita

elphinstonia): to 90cm tall, yellow flowers with purple spots.

●● C. sinensis (syn. Primulina dryas):

dark green ovate bristly hairy dark green leaves to 20cm long, sometimes with silver veins; tubular white flowers not particularly profuse.

●● C. tamiana (syn. Primulina tamiana):

white flowers with purple stripes in the throats.

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CHRYSOTHEMIS Comprises seven species of tuberous plants from tropical America; Chrysothermis pulchella is perhaps the most commonly cultivated species. A dark-leaved form (commonly known as ‘Copper Leaf’) is particularly striking. This species grows into a small shrub: an indoor plant, or in frost-free climates sometimes an outdoor plant.

Chrysothemis pulchella

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●● Water moderately. It can be prone

to root rot if overwatered, or suffer stress if conditions become dry.

●● Prefers part to full shade.

Commonly cultivated species: ●● Chrysothemis pulchella – attractive,

large, dark green leaves, the orange flowers have a bright yellow calyx with red stripes to the throat.

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COLUMNEA Around 150 species including evergreen shrubs, subshrubs, climbers and groundcovers included in this genus. indigenous to woodland and rainforests of Central America the Caribbean and tropical South America. Tubular twolipped flowers are commonly shades of red, yellow or orange. Columnea plants are grown most commonly as a greenhouse or indoor plant in temperate and sub-tropical climates but sometimes as an outdoor plant in warmer places. ●● Night temperatures in winter should

be kept at around 13 degrees Celsius or higher.

●● They like lots of light, but no

direct sunlight. Water freely when growing strongly; but sparingly as growth slows.

●● Flowering occurs late winter or

spring. Repot plants every second year, after flowering.

●● Susceptible to aphis mealy bug,

with dark green foliage, and red flowers with orange to yellow markings. ●● C. crassifolia: a small upright shrub

to 30cm tall, and 30cm diameter; shiny dark green leaves with a pale yellow-green undersides. Hairy bright scarlet flowers occur spring and summer.

●● C. gloriosa: trailing plant, dark

foliage and red flowers.

●● C. microphylla: smaller leaves,

red flowers, trailing stems to 1 metre long.

●● C. hirta: stems to 90cm with hairy

green leaves and very freely flowering with orange-red flowers.

●● C. hirta ‘Light Prince’: a cultivar with

variegated leaves and bright orange flowers.

●● C. scandens: to 15cm tall with

trailing stems to 50cm or more long; hairy red or yellow flowers in spring to summer.

mites and fungal diseases.

●● Prune back stems after flowering. ●● Trailing types are ideally suited to

container growing; particularly as a hanging basket plant.

●● Propagate from root tip cuttings with

bottom heat during spring.

Popularly cultivated species include: ●● Columnea x banksii (a hybrid of C.

schiedeana and C. oerstediana):

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Columnea hirta ‘Light Prince’

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CYRTANDRA The largest genus of gesneriad, Cyrtanda includes includes over 600 species of shrubs and small trees from Asia and the Pacific. Leaves are commonly leathery. Flowers are tubular and for most species white but sometimes red or yellow.

EPISCIA (syn. Alsobia) Six species from Mexico to South America: these can be epiphytic or terrestrial, and are usually creeping or mat forming perennials. ●● Drainage is critical. Do not

overwater, particularly in winter. It does however need high humidity, and that fact has prevented it from becoming as popular as Gloxinias, Streptocarpus and African Violets.

●● Avoid temperatures below 13°C

during winter.

Episcia sp.

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●● Provide bright light over summer; but

never direct sunlight.

●● Surround the plant with moist peat or

sphagnum moss; and if need be, mist to maintain a high humidity if needed.

●● Propagate by sowing ripe, fresh seed

at 20-25°C; by division or by root cuttings over bottom heat.

The two most commonly cultivated species are: ●● E. cupreata: tubular orange to

red flowers with a yellow centre. A range of hybrids have been developed from this species which have variations in foliage colour.

●● E. dianthiflora: this species has

larger flowers than E. cupreata. Flowers are white with a fringed edge to petals.

There are several named cultivars of these species also grown.

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GESNARIA Gesnaria includes around 50 species, indigenous to tropical America and the Caribbean.

Most are tuberous perennials or subshrubs, but some are trees. ●● Minimum winter temperature should

be 13°C, and in summer, ideally 30°C or lower.

●● Propagate by sowing seed at 20-24°C

or from stem or leaf cuttings in spring.

Commonly cultivated species include: ●● Gesnaria cuneifolia: erect or

decumbent plant with large shiny, wavy edged leaves; tubular pink or deep red flowers.

●● G. pedicellaris: to 90cm tall with dark

green leaves; orange tubular flowers with dark lip.

●● G. zebrina (syn. Smithiana zebrina):

Gesneria sp.

Gesnaria pedicellaris

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with caudate (heart-shaped) hairy dark green leaves splashed with purple across the veins; bright red and yellow tubular flowers with dark spots.

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KOHLERIA

NEMATANTHUS

This genus comprises of over 50 species of herbs and shrubs, commonly with hairy stems and leaves. The flowers are sometimes compared to foxgloves and usually appear in small clusters.

Around 25 species from Brazil; formerly classified in the genus Hypocyrta. Most grow as a shrub or vine-like plant, typically with glossy leaves and pouched flowers.

●● Kohleria amabalis: a widely

cultivated species as an outdoor shrub in gardens across England, Australia, the USA and many other countries. It has many named cultivars. Plants grow to 30 to 60cm tall and 30cm wide. The deciduous serrated leaves have purple marks on the veins. The hairy, pendant flowers are deep pink with purplish spots.

●● K. bogotensis: to 30 to 60cm tall

and 30cm wide, with dark green, ovate, deciduous leaves with silvery markings and reddish undersides. Flowers are orange except the three bottom petals which are yellow splashed with red.

●● K. eriantha: to 60 to 90cm tall and

30 to 45cm wide, with elliptic, green, deciduous leaves with purplish hairs. Stems are upright and dark red. Flowers are dark red with yellow spots on the three lower petals.

NAUTILOCALYX This genus comprises of around 25 species from South America grown mostly for their colourful foliage. Nematanthus gregarius variegata

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NIPHAEA (syn. Meneghinia) Only a few species have been identified in this genus they are indigenous to tropical America and have characteristic

Niphaea oblonga

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scaly rhizomes. Leaves are hairy. They are terrestrial plants from damp shady sites in forests. N. oblonga is the best known species.

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RHYNCHOGLOSSUM (syn. Klugia)

●● Water in very dry weather, but these

Around 15 species, this is the only genus that occurs in both Asia and the Americas. Stems are succulent and the flowers are typically dark blue and white.

●● Very susceptible to slugs and snails.

RAMONDA (sometimes spelled ‘Ramondia’)

●● Grows well as a containerised plant

There are three species, indigenous to Europe; all small herbs from mountainous locations. Hairy leaves. Flowers often slightly two-lipped. ●● Grow in a well-drained organic soil. ●● Avoid direct sun. A position facing

away from the sun, or in part shade is ideal.

plants come from drier climates than many of the other gesneriads, will tolerate drier conditions.

●● Propagate from fresh seeds or root-

leaf cuttings in early autumn. or rockery plant.

Species include: ●● Ramonda myconi (syn. R.

pyrenaica): dark green, slightly crinkly dark green leaves; rosette forming, evergreen, dark violet blue flowers with yellow anthers.

●● R. nathaliae: glossy pale green

leaves, slightly crinkled.

●● R. serbica: pale green leaves to 5cm

long, lilac blue flowers.

Niphaea oblonga

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Saintpaulia (African Violet) At one time more than 20 species of African Violets were identified in this genus, all indigenous to tropical East Africa. Nowadays, the thinking is leaning back towards fewer actual species. The African Violet Society of America suggests that there are 9 different species. Many of those thought to be separate species have been found through DNA testing to be subspecies of S. ionantha and that the majority of those commonly cultivated are hybrids of crosses of S. ionantha and S. confusa. All African Violets are low-growing, evergreen perennials, commonly occurring alongside watercourses, and sometimes epiphytic. Most do not look as though they have stems (but actually have very short stems), and some trailing types have extended stems. Thousands of named cultivars exist, mostly bred from S. ionantha.

African violets

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African violets

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Saintpaulia, the African Violet

Classification Systems and Changes to Classifying Saintpaulia

Many of the genera and species names of gesneriads (and other plants) are changed from time to time by these experts. If one congress retains an old name and another implements a change we can potentially have the same plant with two different names – and arguably both are equally acceptable.

There are many different ways of classifying African Violets that are in cultivation.

Beyond the classifications of these academics, there are many other organisations around the world that periodically develop ways of classifying plants. One such example is the African Violet Society of America, which developed a classification system that divided African Violets into species, subspecies and clones. More recently, research based on genetic studies the International Society for Horticultural Science has suggested that Saintpaulia should be listed as a subspecies (section) of Streptocarpus, to which it is closely related. This proposed change needs to be ratified by numerous other entities before it can go ahead.  

The scientific system of classifying plants follows rules established by the 18th century Swedish botanist, Linnaeus. Changes to this system are managed by international meetings of scientists. While this system is no doubt the most accurate, it is still not always 100% consistent. There is an international congress of botanists which makes decisions, but also an international congress of horticulturists which makes decisions. Some academics will follow one of these groups in preference to another; even though they both agree most of the time, sometimes they do not. page 43

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The result of other recent studies has reduced the number of original (20) species in the genus Saintpaulia to 6. This is because the original species included within the genus were not well distinguished in terms of their genetics and morphology (i.e. the form, shape and structure) of the species. Floristic studies were undertaken in 2009 and the result is that the majority of the former species within S. ionantha have been reduced to subspecies. The result is 9 species, 8 subspecies and 2 botanical varieties have been recognised.

Saintpaulia ‘Integrity’

Size Classifications of Saintpaulia Species

Saintpaulia ‘Crystal Gazer’

Saintpaulia are also classified according to size. There is more than one system used and the process has as yet not been ratified across the board. The plant is measured across a single crown.

Note: botanical varieties are natural variants of the species or subspecies not cultivated varieties. Definitions ●● Peduncle: the main stalk of a flower

or fruit.

●● Petiole: the stalk that joins a leaf to

a stem.

●● Clone: genetically identical to the

parent plant as produced through asexual (vegetative) propagation.

●● ssp. stands for subspecies. page 44

Saintpaulia ioantha rupicola

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A general guide to size categories: ●● Miniature: plant crown less than 15

– 20cm diameter when measured across the crown when fully mature; flowers are 2cm across and each leaf 2.5cm long. Some experts also further categorise miniatures into super mini: crowns 7.5 – 10cm and micro-mini: crowns are less than 7.5cm diameter

●● Semi-miniature: plant crown 15-

20cm at maturity; flowers 3.75cm across and each leaf is 5cm long.

●● Standard: 20 – 40 cm when fully

mature when measured across the crown; flowers are to 5cm across and each leaf to 7.5cm long

●● Large: over 40 cm when fully

mature; flowers are 7.5cm across and each leaf to 15cm long

Saintpaulia Species and Their Newer Classifications Note: in the following the old name has been listed first and the newer classification is after the = sign. S. amanienis = S. ionantha ssp. grotei: see further notes below in the section on ionantha species. S. brevipilosa = S. ionantha ssp. velutina: Single flowers which are light purple with a darker centre; 1-4 per peduncle, very short-lived. Light green, small, round, thin, glossy, soft, velvety, tightly bunched/pale back; randomly curved petioles. Usually has a single crown. Miniature to small standard. S. confusa = S. ionantha ssp. grotei: see further notes below in the section on ionantha species. Saintpaulia difficilis = S. ionantha ssp. grotei: see further notes below in the section on ionantha species. S. diplotricha = S. ionantha ssp. ionantha var. diplotricha: see further notes below in the section on ionantha species. S. grandiflora = S. ionantha ssp. grandifolia: see further notes below in the section on ionantha species. S. grotei = S. ionantha ssp. grotei: see further notes below in the section on ionantha species. S. intermedia = S. ionantha ssp. pendula: see further notes below in the section on ionantha species.

Saintpaulia ioantha ssp grotei

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S. ionantha (syn. S. kewensis): see further notes below in the section on ionantha species.

S. pendula var. kizarae = S. ionantha ssp. pendula: see further notes below in the section on ionantha species. S. rupicola = S. ionantha ssp. rupicola: flowers are single light-medium blue, three or more per peduncle. Lightmedium green, heart-shaped, soft, smooth, glossy, velvety/light back. Leaves sometimes thick. Multi-crowned standard or bushy trailer.

Saintpaulia ioantha ssp. grotei

S. 8 clone ‘Kacharonoroni’: flowers single pale blue to mauve, 4-8 per peduncle. The leaves are oval, slightly fleshy, medium green above, pale green to whitish beneath, edges smooth or shallowly wavy, upper surface hairy. A standard rosette or sometimes multiple crowns.

S. manungensis = S. ionantha ssp. grotei: see further notes below in the section on ionantha species. S. magungensis var. minima = S. ionantha ssp. grotei Saintpaulia magungensis var. occidentalis = S. ionantha ssp. occidentalis S. nitida = S. ionantha ssp. nitida: single dark blue-purple flowers, 8-10 per peduncle, floriferous. Dark green, round, may spoon, smooth, glossy, slender brown petiole/red back. Open growth; small or bushy trailer or multi-crowned standard. S. orbicularis = S. ionantha ssp. orbicularis: see further notes below in the section on ionantha species. S. pendula = S. ionantha ssp. pendula: see further notes below in the section on ionantha species. page 46

Saintpaulia ‘Jay’s Aussie Belle’ S. shumensis: a rare plant from Tanzania where it grows at altitudes from 1300 – 200 metres above sea level and in the wild it is considered an endangered species. Growth habit is a single crown, with a tendency to produce suckers, on a miniature to semi miniature size plant. Flowers are a single pale blue – white colour with a variable darker eye. Usually there are 4 flowers

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per peduncle. Flowering is sparse. Leaves are bright green, pebbled, glossy, slightly serrated, short petiole, leaf blade twisted in some clones.

S. velutina = S. ionantha ssp. velutina

More about S. ionantha As can be seen from the listings above S. ionantha is divided into several subspecies as outlined below: S. ionantha ssp. grandifolia Clones include: ●● S. grandifolia #237 1958 (B. Burtt):

Saintpaulia ‘Light Years’ S. teitensis: a rare species plant from Kenya restricted to a single square kilometre on the locality of Mbololo Hill in the Taita hills in the south of the country. It is estimated that less than 2500 plants exist in the wild. Flowers are 4-8 per stalk and dark blue; leaves thick, leathery and dark green with (often) raised veins smooth margins and red undersides. Saintpaulia tongwensis = S. ionantha ssp. ionantha var. ionantha

single blue-violet, one or more per peduncle, floriferous. Light green, elliptical, very thin, long flexible petiole. Usually single crown. Large.

●● S. grandifolia #299 1958 (B. Burtt):

single dark blue-violet, one or more per peduncle, very floriferous. Light to medium green, elliptical, very thin, crinkled, long flexible petiole. Usually single crown. Large.

S. ionantha ssp. grotei Clones include: ●● confusa 1958 (B. Burtt): single dark

purple, 2-6 per peduncle. Variable in floriferousness. Medium green, thin, quilted, leathery, flexible, serrated/ near-white back. Often multi-crowned; may develop sideways growth habit. Semi-miniature to standard.

●● grotei: single, light-medium blue

Saintpaulia tongwensis

page 47

flower with variable darker eye, 2-3 per peduncle, often obscured by leaves. Pale-dark green, variable texture, round, serrated on most clones. Usually near-white back, occasionally red. Green or brown flexible petiole. Large trailing plant.

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●● magungensis var. minima: single tiny

light purple flowers with darker eye, 1-2 per peduncle, rarely blooms. Leaves medium, small, cuppeddown, thin, hairy, serrated, redbrown petiole.

mottled, longifolia, may spoon, thick, tough, very hairy, varies in size/ purple-red back. Multi-crowned. Large clump or bushy trailer. ●● var. tongwensis: single pale blue

flowers, may have dark pinwheel marking in cool temperatures; 4-6 per peduncle, very floriferous. Dark green, pointed, narrow, very thick, hairy, slightly serrated/some red back. May appear variegated with mottled pattern over main veins. Usually upright single crown; rarely suckers. Standard.

S. ioantha ssp. ionantha var. diplotricha ●● diplotricha (Parker): single pale lilac

flowers with bright yellow stamens; seven per peduncle.

Saintpaulia ‘Monet’ S. ionantha ssp. ionantha ●● ionantha: single blue-violet flower,

4-5 per peduncle, very floriferous. Dark green, pointed, heart-shaped, tends to spoon, thick, quilted, glossy, slightly serrated, long redbrown petiole/red back. Large.

●● ‘House of Amani’: single medium

lavender-blue, 3-7 per peduncle, hides under leaves, short-lived. Dark green, pointed, quilted, smooth, prominent veins, serrated/occasional red back, petiole. Usually single crown. Standard size.

●● ‘Sigi Falls’: single variable blue-

violet flowers, 2-4 per peduncle, sometimes flowering difficult. Leaves dull green, tends to look

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S. ionantha ssp. orbicularis ●● orbicularis var. purpurea: single

small dark purple, 5-8 per peduncle, very floriferous. Dark green, round to heart-shaped, thin, glossy/light back. Single or multiple crown. Standard.

S. ionantha ssp. pendula ●● intermedia: single medium blue

flowers, 5-7 per peduncle, sparse. Olive green, small, round, tends to spoon, velvety, slightly serrated/ purple-red back, prominent green veins. Single crown to trailing. Small standard or trailer.

●● S. pendula var. kizarae 3397: It

has a trailing habit and single lavender flowers, 2- 4 per peduncle; floriferous. Light green, round, hairy, serrated.

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S. ionantha ssp. velutina ●● velutina: flowers single small

medium violet/darker eye, some white tips; five per peduncle, floriferous. Black-green, round to heart-shaped, may cup up or down, thin, hairy, velvety, pronounced veining, serrated/red-purple back.

●● Velutinalite: semi-double white

flowers tinged with blue. Leaves unusual; are crinkled and velvety dark green, pointed, thick and serrated. Single crown, may sucker.

Saintpaulia ‘Opt Trinidad’

Saintpaulia ‘Ode to Beauty’ Saintpaulia ‘Pac Sui’

Saintpaulia ‘Okie Easter Bunny’

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Saintpaulia ‘Powder Keg’

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Saintpaulia ‘Rhapsody Rosalie’

Gloxinia sp.

Saintpaulia ‘Sweet Charity’

SINNINGIA (GLOXINIA) Around 75 species are included in this genus according to Hortus Third; but more recent genetic analysis shows Sinningia and some other gesneriads have not been classified in a way that properly reflects their natural relationships. There have been changes in the past to the classification of Sinningia, and it is likely there will be further changes in the future; some were previously known under the genus name Gloxinia or Rechsteineria. page 50

Gloxinia flower

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Sinningia leucotricha They include both perennial and deciduous plants from tropical Central and South America. Most have a small to large woody tuber; a couple have rhizomes rather than tubers. Leaves occur on short stems or arise direct from the tuber. ●● Average minimum temperature over

winter should be around 15 degrees Celsius. Most grow best at 18 to 24°C.

●● Do not water with cold water, even

in summer. Always use tepid water. Cold water (or overwatering) can cause rot to develop.

●● Reduce watering and stop feeding

over winter; but be sure to water and feed plants when growing strongly. Flowering can be halted if exposed to dry air or draughts. Keep away from open windows, air vents etc.

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Gloxinia hybrida Species Include: ●● Sinningia barbata: small shrub to

30cm tall with red-brown stems and glossy dark blue green leaves that are red to purple and hairy underneath. White flowers.

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●● S. cardinalis (syn. Gesneria

cardinalis, common name: Cardinal Flower) – grows best at 19°C; tubular blood red flowers.

●● S. cauescens: sage green densely

woolly leaves, growing to 30cm tall and 35cm wide. Pinkish orange to red or rose-pink flowers.

●● S. warmingii: one of the largest

plants in the genus stems reaching up to 30cm high, the caudex up to 5cm across and producing pale red flowers. Propagate by seed or cuttings.

●● S. pusilla: grows best at 19°Celsius.

A small plant to 5cm tall and 5cm wide; nodding tubular lilac flowers with white throats.

●● S. regina: to 20cm tall and 35cm

wide; dark green velvety leaves with paler green veins, nodding rich purple flowers.

●● S. speciosa (common name:

Brazilian Gloxinia or Violet Slipper): to 30cm tall and 30cm wide; dark green velvety leaves with a reddish under surface; flowers in the wild are violet to red or white. In cultivation they are divided into three groups: 1. Speciosa group – wild forms with small, nodding flowers 2. Maxima group – similar to the speciosa group, but with a wider variety of flower colours 3. Fyfiana group – syn. G. x hybrida – many named cultivars in this group

●● S. tubiflora (syn. Achimenes

tubiflora): hairy green leaves to 12cm long, fragrant white flowers around 2cm long.

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Gloxinia hybrida

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SMITHIANTHA (Temple Bells) Smithiantha includes four species of rhizome forming plants from moist tropical woodlands and rock microclimates in Mexico. Heart shaped fleshy leaves. It produces clusters of nodding red, orange or yellow flowers. ●● Ideally keep temperature around

19 to 20°C summer to autumn and never below 10°C during winter.

●● When dormant over winter, keep

plants completely dry.

●● Some are annuals and will naturally

die after fruiting.

●● Susceptible to a range of pests,

including: mealy bug, thrips, mites, leafhoppers, and vine weevil larvae.

●● They are popular container,

greenhouse and indoor plants amongst home gardeners and collectors.

●● To propagate; sow seed late winter

or spring at 18°C; or grow from leaf cuttings or root-stem tip cuttings.

●● Susceptible to aphids. ●● Propagate from seed sown at 15 to

18°C or dividing rhizomes in spring.

Species include: ●● S. cinnabarina (syn. Naegelia

cinnabarina): heart-shaped deep green leaves, with dense red hairy surface red flowers with paler to white spotted throats.

●● S. zebrina (syn. Gesnaria zebrina):

to 75cm tall and 35cm wide; heartshaped deep green leaves, Yellow and scarlet coloured flowers.

STEPTOCARPUS (Cape primrose) There are around 132 species of Streptocarpus and many hundreds if not thousands of named varieties. They are indigenous to Asia, Africa and Madagascar. Many are perennials. ●● Growth habit is creeping or erect.

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Streptocarpus ‘Frosty Diamond’

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Streptocarpus ‘Gwen’

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Streptocarpus ‘Hannah’

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Streptocarpus ‘Harlequin Damsel’

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Streptocarpus ‘Blue Frills’

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Species Include: ●● S. caulescens: to 60cm wide, deep

brown stems, soft hairy leaves, violet or white flowers.

●● S. dunii: large grey-green leaves

can get to 30cm long. A plant may only produce a single leaf. Plants produce a cluster of pinkish orange to red flowers, and typically die after one flowering season. They grow best in bright but indirect sunlight.

●● S. x hybridus (common name:

Cape primrose): this refers to a complex group of cultivars created by hybridising a number of different species. Many named cultivars fall under this name such as the ‘Weismoor’ hybrids.

Streptocarpus ‘Nia’

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●● S. primulifolius: rough, hairy leaves

grow from a rhizome, then individual leaves develop their own roots and flowering stems. It is fast growing, loves shade and is popularly cultivated as an indoor or garden plant.

●● S. rexii: to 50cm wide, violet flowers

may or may not be tinged white; blunt tips on soft hairy leaves to 20cm long.

●● S. saxorum: to 60cm wide, sparsely

branched, thick grey-green, fine, hairy leaves to 2.5cm long; with pale lilac, white-throated flowers.

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Also, a large number of named cultivars exist.

Streptocarpus ‘Polka Dot Purple’ Streptocarpus ‘Spirit’

Streptocarpus saxorum compact

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Streptocarpus ‘Sweet Melys’

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Streptocarpus ‘Targa’

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Streptocarpus ‘Tina’

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